Fattening Pigs with Tannin-Rich Source (Ceratonia siliqua L.) and High Doses of Vitamin E: Effects on Growth Performance, Economics, Digestibility, Physiology, and Behaviour.

Simple Summary: To ensure long-term sustainability, the meat industry seeks to apply more sustainable practices like replacing imported traditional feedstuff (i.e., cereals) with low-cost local resources. In this sense, carob pulp (Cp), a Mediterranean by-product rich in polyphenols, represents a potential alternative to feed pigs. Polyphenols exhibit antioxidant properties comparable to vitamin E (Vit E) but may impair animal growth in high doses. This study evaluated the influence of supplementing fattening pig diets with 20% Cp and high doses of Vit E (300 IU/kg) on growth performance, economic results, physiological parameters, nutrient digestibility, and animal behaviour. While no synergistic effect between Cp and Vit E was observed, incorporating 20% Cp in pig diets during the last 40 days of the fattening period is feasible without compromising growth performance, physiology, or behaviour. However, crude protein digestibility and the feeding cost were negatively affected by Cp inclusion. Supplementation with Vit E, although not improving pig performance, increased α-tocopherol deposition in blood, potentially enhancing the antioxidant tissue profile and meat quality. This study aimed to assess the impact on growth, economic results, apparent nutrient digestibility (CTTAD), physiological variables, and animal behaviour when 214 fattening pigs (78 ± 8.5 kg of initial body weight and 130 ± 4.5 days of age) of both sexes (gilts and boars) were fed two levels of carob pulp (Cp, 0 vs. 20%) and two doses of vitamin E (Vit E, 30 vs. 300 IU/kg) for 40 days. No interaction effects between factors studied (Cp, Vit E, and sex) were observed on the variables. Most productive traits were unaffected by Cp or Vit E inclusion. However, the Cp increased the feed conversion ratio during the first 20 days. The Cp group showed a higher CTTAD of ether extract and hemicellulose but lower CTTAD of crude protein. Pigs fed Cp had a lower plasmatic urea content than the control group. The high Vit E doses increased the CTTAD of every nutrient and the plasmatic α-tocopherol content. The pigs fed Cp tended to spend more time eating in the early morning, likely to mitigate tannins' astringent effects. Dietary inclusion of 20% Cp in finishing high-conformation pigs is possible without affecting overall performance though it reduces nutrient CTTAD and increases feeding cost. Supra-nutritional doses of Vit E do not affect pig performance but increase the α-tocopherol deposition with potential antioxidant effects. [ABSTRACT FROM AUTHOR]